1. Field of the Invention
The present invention pertains to a zoom lens system, and more particularly to a zoom lens system suited for a silver halide film cameras and a digital cameras.
2. Description of the Related Art
A zoom lens systems in which the first lens unit located closest to the object has a positive refractive power and said first lens unit moves during zooming and focusing are conventionally known. This conventional zoom lens system, however, has a problem that it is difficult to ensure adequate light for peripheral areas when it is in focus on a close-range object. Because of this problem in, light for peripheral areas have been conventionally secured while the lens system is in focus on a close-range object by means of increasing the effective diameter of the first lens unit.
However, with a conventional zoom lens system, flaring occurs when the lens system is in focus on an object located at infinity.